ITP (immune thrombocytopenia) Causes

ITP is an autoimmune disease that attacks the body's own platelets.1,2 Platelets are small cells in the blood that help it to clot, which helps stop bleeding.3 Platelet destruction in ITP causes your normal platelet count to drop below what it should be. If your platelet count is too low, bruising and severe bleeding may occur.1,4

The cause of ITP is unknown, but the disease involves two processes. Together, these 2 processes are the reason your platelet count is below normal.2,5-7 Treating either process has been shown to raise platelet counts.

  1. Normal platelet production
    • A protein in the body called thrombopoietin, or TPO, is necessary to make platelets.5,8
  2. In ITP, the immune system destroys healthy platelets
    • Antibodies* in the immune system attach to platelets.2
    • This causes the spleen to remove the platelets from the body.2
  3. In ITP, not enough platelets are made
    • Antibodies* damage platelet-producing cells in the bone marrow, so they don’t make enough platelets.9
    • A protein in the body called thrombopoietin, or TPO, is necessary to make platelets. In ITP, TPO levels do not go up enough when platelet levels are low.5,8

* Antibodies are proteins made by the body’s immune system to attack foreign cells.10

What are platelets and thrombopoietin?

Platelets are small cell-like particles that are made in the bone marrow by another type of cell called megakaryocytes. Platelets circulate through the bloodstream and help stop bleeding by forming clots when blood vessels are damaged.3

A platelet is usually removed from the bloodstream in about 10 days. In an adult patient with ITP, antibodies cause platelets to be destroyed much sooner—sometimes only a few hours after they enter the bloodstream. Antibodies may also attack the megakaryocytes, which may prevent these cells from making as many platelets as they typically would have.11

Thrombopoietin (TPO) is a protein made predominately in the liver that controls how many platelets are made by the body. When platelet counts are normal, the right amount of TPO properly signals the bone marrow to make platelets at a rate to keep platelet counts level.5,7

In people with ITP, however, the amount of TPO is not high enough to properly signal the bone marrow to make enough platelets to make up for the ones that have been destroyed.8

Talk with your doctor about your symptoms and ITP treatment options
Prepare for doctor visit
Nplate® may help your body make more platelets
*Learn about dosing and monitoring

Learn about Nplate®
Talk with your doctor about your symptoms and ITP treatment options
Prepare for doctor visit
Nplate® may help your body make more platelets
*Learn about dosing and monitoring

Learn about Nplate®